Abstract: The cost-effective thermal energy storage will play an important role for the economic success of concentrating solar power plants. One option to significantly reduce costs is to use thermocline storage systems. Based on the idea of thermocline thermal storage，a molten-salt hybrid thermocline thermal storage system was developed in this paper，which was a single thermal storage tank，where a thermocline was in the middle section of the tank，a high-temperature PCM (phase change material) heat exchanger of shell and tubes was placed on the top of the tank and a low-temperature PCM heat exchanger of shell and tubes was placed on the bottom of the tank. The thermocline，a thermal gradient，potentially separated hotter molten-salt liquid from colder molten-salt liquid in the same tank. The high and low temperature PCM heat exchangers of shell and tubes would not only increase the thermal storage capacity of the system，but also simplify the molten-salt liquid charging and discharging structure. The preliminary experiments determined the amount of effective thermal storage capacity of the system and substantiated that the thermocline could keep stable during charging and discharging cycle and demonstrated the promising prospect of this thermal storage option.